The next evolution in wireless networking holds promises of self-driving cars and movies that download in the blink of an eye. 5G is big at this year's Mobile World Congress, but don't expect it until 2020.

From long-expected new products like the Samsung Galaxy S6 and HTC One M9 to surprises like the Huawei Watch and HTC Vive, here's everything you missed on the day before the Mobile World Congress officially opened.